Explicit as-path filtering (with prepending allowed)

[Wilco Baan Hofman]

On 19/09/2019 06:42, Nigel Kukard wrote:
> Hi guys,
> 
> Is there perhaps an equivalent in BIRD for the following...
> 
> ^(65000_)+(65101_)+(65253_)+$
> 
> The closest I could come was the following, but I am unsure if it
> would match if any of the networks prepend.
> 
> if (bgp_path ~ [= 65000 65101 65253 =])

This would be correct, but would not match routes with prepends. It
would be useful to have this indeed.

Easiest way to implement would probably be to have a deduplicated
attribute with only distinct ASes in the path, something like
if (bgp_path.distinct ~ [= x y z =]) syntax or something similar, but
this is not possible (correct me if I'm wrong).


-- Wilco